In the past it has been well known in multiple disk brakes to provide an assembly in which a stack of brake disks are carried inside a wheel rim with the rotatable disks being keyed to keyslots provided around the inner surface of the wheel rim opposite the bead seat as shown in Nelson et al U.S. Pat. No. 3,650,357. In some instances, however, the diameter of the wheel does not provide sufficient room to place the brake disks inside the wheel rim. In such instance an alternative arrangement is to provide a cylindrical flange extending axially inwardly from the inner edge of the wheel rim and having keyslots in the circular flange to engage radially outwardly extending ears on the rotatable disks and cause the disks to rotate with the wheel. An example of a brake using such a cylindrical driving flange with open ended keyslots is shown in U.S. Pat. No. 3,438,464 to C. E. Barrington. In some instances it may be desirable to have a cylindrical driving flange extending axially from both sides of the wheel. Such an arrangement with the open ended keyslots is satisfactory when used with only a small number of brake disks. When the brake requires a large number of rotary disks to be keyed to a cylindrical member on the wheel and the keyslots are open ended, there is a tendency for the portions of the cylindrical member between the keyslots to bend radially outwardly when there is a large amount of heat build up in the wheel rim and cylindrical member and the brake is subjected to torque loads or rolling loads. This problem can occur in an airplane brake overheated from landing or a rejected take-off while taxiing back to the hanger.